ENTRY 20767 20101112 22252076700000001 SUBENT 20767001 20101112 22252076700100001 BIB 18 119 2076700100002 INSTITUTE (2GERKFK) 2076700100003 REFERENCE (J,NSE,69,(1),39,197901) Main reference. 2076700100004 (W,Kaeppeler,19820309) Correction factors for data 2076700100005 points communicated to NEA DATA Bank. 2076700100006 (W,Wisshak,19780803) Attached preprint gave 2076700100007 informations on apparatus and data. This paper is 2076700100008 accepted for publication in NSE. 2076700100009 (P,KFK-2504,24,197710) Abstract given. 2076700100010 REL-REF (I,20765001,K.Wisshak+,J,NSE,66,(3),363,197806) Details2076700100011 on method and apparatus are given. 2076700100012 AUTHOR (K.Wisshak,F.Kaeppeler) 2076700100013 TITLE -Neutron capture cross-section ratios of Pu-240 and 2076700100014 Pu-242 versus Au-197 in the energy range from 50 2076700100015 to 250 keV- 2076700100016 FACILITY (VDG,2GERKFK) Karlsruhe 3 MV pulsed accelerator 2076700100017 provided protons with pulse width of 700 psec,with a 2076700100018 repetition rate of 5 MHz,with an average current of 2076700100019 15 microA. The proton energy was chosen 100 keV 2076700100020 above the n-source reaction threshold at 1019 keV. 2076700100021 INC-SOURCE (P-T ) The water-cooled neutron target consisted of 2076700100022 a tritium loaded titanium layer(12.5mm diam,2.1micron 2076700100023 thick),evaporated onto a 0.3 mm thick tungsten 2076700100024 backing and protected by an evaporated layer of 2076700100025 50 micrograms/cm**2 aluminium. 2076700100026 .The specific target activity was 0.8 Ci/cm2. 2076700100027 .the energy range of neutrons was up to 250 keV. 2076700100028 .All neutrons were emitted from the target into a 2076700100029 cone in forward direction with an opening angle 2076700100030 of 120 degrees. 2076700100031 SAMPLE .The following table summarizes the relevant sample 2076700100032 data.(For the chemical and isotopic composition see 2076700100033 NSE,66) 2076700100034 sample meas.No weight(g) thickness(atom/b) 2076700100035 Pu-240 1,2 3.038 0.000952 2076700100036 Pu-242 1 10.705 0.00333 2076700100037 2 8.744 0.00272 2076700100038 Au-197 1 13.545 0.00586 2076700100039 2 13.209 0.00571 2076700100040 U-235 1 7.649 0.00277 2076700100041 2 9.066 0.00328 2076700100042 graphite 1 0.547 0.00388 canned,dummy(240) 2076700100043 1.55 0.0110 canned,dummy(242) 2076700100044 2.02 0.0143 uncanned,dummy(197) 2076700100045 2 1.778 0.0126 canned,dummy. 2076700100046 METHOD (TOF ) With kinematically collimated neutrons due to 2076700100047 the center-of-mass movement of the compound nucleus. 2076700100048 .The flight path was 65 mm long. 2076700100049 .A set of four samples were mounted on a sample changer2076700100050 and cycled automatically into the measuring position. 2076700100051 The cycle time was determined by integrating the beam 2076700100052 current to a preselected charge. 2076700100053 .A dummy sample was used to correct for background 2076700100054 events and a U-235 sample served for normalization 2076700100055 of the fission correction. 2076700100056 .The capture cross-section ratios of Pu versus Au-197 2076700100057 have been measured twice for each isotope.In the 2076700100058 first measurement a metallic Au-197 disc was used 2076700100059 while in the second one it was canned in a 2076700100060 polyethylene foil to avoid against neutron scattering 2076700100061 in the envelope of Pu samples. 2076700100062 .The parameters of the individual measurements are 2076700100063 as follows,I to IV runs for 1st meas,V and VI for 2nd,2076700100064 run sample1 sample2 sample3 sample4 MNE(keV) F.P.(mm) 2076700100065 I Pu-240 dummy0 U-235 Au-197 210. 66.0 2076700100066 II Pu-242 dummy2 U-235 Au-197 250. 66.0 2076700100067 III dummy0 - U-235 dummy7 250. 66.0 2076700100068 IV dummy7 Au-197 Au-197C dummy7C 250. 62.8 2076700100069 V Pu-240 dummy Au-197C U-235 250. 66.0 2076700100070 VI Pu-242 dummy Au-197C U-235 250. 67.6 2076700100071 .the MNE is the maximum neutron energy,F.P.-the flight 2076700100072 path,dummy0 the dummy sample for Pu-240,dummy2 for 2076700100073 Pu-242,dummy7 for Au-197 suffix C means canned with 2076700100074 polyethylene foil. 2076700100075 DETECTOR (MOXR ) With a 25 mm thick graphite converter used for 2076700100076 registration of gamma-rays from capture and fission 2076700100077 events 2076700100078 (SCIN ) fission neutron detector using a NE-213 2076700100079 liquid scintillator with pulse-shape discriminator 2076700100080 equipment,used to correct data for fission events. 2076700100081 .Both detectors were shielded with lead and were 2076700100082 located at backward angles of 120 deg with respect 2076700100083 to the beam axis.They were completely outside the 2076700100084 neutron cone. 2076700100085 ANALYSIS .See NSE,66. 2076700100086 COMMENT .Curves were given too. 2076700100087 ADD-RES (COMP) Authors made a comparison with other 2076700100088 experimental or evaluated data.Discrepancy were found 2076700100089 with ENDF/B-IV evaluation files. 2076700100090 FLAG (1.) Data refer to the first measurement. 2076700100091 (2.) Data refer to the second measurement. 2076700100092 CORRECTION .Corrected for multiple scattering,self shielding, 2076700100093 time spread,time-dependant and constant background, 2076700100094 fission events in the Pu samples,and neutron beam 2076700100095 intensity. 2076700100096 .The assumption that the shape of the capture gamma- 2076700100097 ray spectra of the heavy nuclei from Au-197 to 2076700100098 Am-241 do not differ too much has been shown to 2076700100099 be wrong and the authors have therefor sent new 2076700100100 correction factors as private communication. Data 2076700100101 have been recalculated using these factors. 2076700100102 ERR-ANALYS (ERR-S) Statistical error. 2076700100103 (ERR-SYS) Systematic error. 2076700100104 (ERR-T) Total error. 2076700100105 In Nucl.Sci.&Ing. 69,(1),39,197901 description of 2076700100106 uncertainties of the second experiment is given. 2076700100107 STATUS (TABLE) .Data have been recalculated with new corr. 2076700100108 factors. Correction factors for data points 2076700100109 communicated to NEA DATA Bank. 2076700100110 HISTORY (19780807C) 2076700100111 (19781024E) 2076700100112 (19800208A) Main reference added. 2076700100113 (19800213E) 2076700100114 (19801112A) G.C., Reaction strings corrected. 2076700100115 (19801121E) 2076700100116 (19820316A) Recalculation of data. 2076700100117 (19820921E) 2076700100118 (20101112A) SD:Updated to new date formats,lower case. 2076700100119 corrected according to last EXFOR rules and Dict. 2076700100120 Code SUM deleted from REACTION (Subents 002,003) 2076700100121 ENDBIB 119 0 2076700100122 NOCOMMON 0 0 2076700100123 ENDSUBENT 122 0 2076700199999 SUBENT 20767002 20101112 22252076700200001 BIB 2 3 2076700200002 REACTION ((94-PU-240(N,G)94-PU-241,,SIG)/ 2076700200003 (79-AU-197(N,G)79-AU-198,,SIG)) 2076700200004 COMMENT .Both measurements are made at a 66 mm flight path. 2076700200005 ENDBIB 3 0 2076700200006 NOCOMMON 0 0 2076700200007 DATA 7 17 2076700200008 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076700200009 FLAG 2076700200010 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076700200011 NO-DIM 2076700200012 4.8400E+01 4.4000E+00 1.2800E+00 7.2000E+00 8.1000E+00 1.0800E+012076700200013 1.0000E+00 2076700200014 4.9100E+01 4.5000E+00 1.3400E+00 8.4000E+00 1.0400E+01 1.3400E+012076700200015 2.0000E+00 2076700200016 5.5300E+01 5.3000E+00 1.3900E+00 6.0000E+00 7.4000E+00 9.5000E+002076700200017 1.0000E+00 2076700200018 5.6200E+01 5.4000E+00 1.3900E+00 7.0000E+00 8.8000E+00 1.1200E+012076700200019 2.0000E+00 2076700200020 6.3900E+01 6.4000E+00 1.2200E+00 5.2000E+00 7.3000E+00 8.6000E+002076700200021 1.0000E+00 2076700200022 6.4900E+01 6.5000E+00 1.1600E+00 6.4000E+00 8.1000E+00 1.0300E+012076700200023 2.0000E+00 2076700200024 7.4600E+01 7.6000E+00 1.1500E+00 4.5000E+00 6.8000E+00 8.2000E+002076700200025 1.0000E+00 2076700200026 7.5700E+01 7.9000E+00 1.2000E+00 5.8000E+00 7.6000E+00 9.6000E+002076700200027 2.0000E+00 2076700200028 8.8200E+01 9.7000E+00 1.0100E+00 3.7000E+00 6.1000E+00 7.1000E+002076700200029 1.0000E+00 2076700200030 8.9600E+01 9.8000E+00 1.2200E+00 4.7000E+00 6.4000E+00 7.9000E+002076700200031 2.0000E+00 2076700200032 1.0600E+02 1.2300E+01 1.1000E+00 3.3000E+00 5.8000E+00 6.7000E+002076700200033 1.0000E+00 2076700200034 1.0760E+02 1.2600E+01 1.2200E+00 4.1000E+00 5.8000E+00 7.1000E+002076700200035 2.0000E+00 2076700200036 1.2980E+02 1.6200E+01 1.0900E+00 3.2000E+00 6.0000E+00 6.8000E+002076700200037 1.0000E+00 2076700200038 1.3170E+02 1.6600E+01 1.1500E+00 3.7000E+00 5.5000E+00 6.6000E+002076700200039 2.0000E+00 2076700200040 1.6250E+02 2.2100E+01 1.1900E+00 3.8000E+00 6.4000E+00 7.4000E+002076700200041 1.0000E+00 2076700200042 1.6490E+02 2.2600E+01 1.1300E+00 3.7000E+00 5.5000E+00 6.6000E+002076700200043 2.0000E+00 2076700200044 2.1250E+02 3.1600E+01 1.0800E+00 6.5000E+00 7.3000E+00 9.8000E+002076700200045 2.0000E+00 2076700200046 ENDDATA 38 0 2076700200047 ENDSUBENT 46 0 2076700299999 SUBENT 20767003 20101112 22252076700300001 BIB 2 4 2076700300002 REACTION ((94-PU-242(N,G)94-PU-243,,SIG)/ 2076700300003 (79-AU-197(N,G)79-AU-198,,SIG)) 2076700300004 COMMENT .First measurement is done with a 66.0mm flight path, 2076700300005 while second with 67.6 mm flight path. 2076700300006 ENDBIB 4 0 2076700300007 NOCOMMON 0 0 2076700300008 DATA 7 16 2076700300009 EN EN-ERR DATA ERR-S ERR-SYS ERR-T 2076700300010 FLAG 2076700300011 KEV KEV NO-DIM PER-CENT PER-CENT PER-CENT 2076700300012 NO-DIM 2076700300013 5.5300E+01 5.3000E+00 1.2300E+00 5.9000E+00 9.7000E+00 1.1400E+012076700300014 1.0000E+00 2076700300015 5.7600E+01 5.6000E+00 1.2800E+00 1.0800E+01 1.0800E+01 1.5300E+012076700300016 2.0000E+00 2076700300017 6.3900E+01 6.4000E+00 1.0700E+00 5.5000E+00 9.8000E+00 1.1200E+012076700300018 1.0000E+00 2076700300019 6.6400E+01 6.7000E+00 9.7000E-01 1.1600E+01 1.1600E+01 1.6400E+012076700300020 2.0000E+00 2076700300021 7.4600E+01 7.6000E+00 1.0500E+00 4.7000E+00 8.2000E+00 9.5000E+002076700300022 1.0000E+00 2076700300023 7.7300E+01 8.2000E+00 9.9000E-01 9.3000E+00 9.9000E+00 1.3600E+012076700300024 2.0000E+00 2076700300025 8.8200E+01 9.7000E+00 8.9000E-01 4.6000E+00 9.4000E+00 1.0500E+012076700300026 1.0000E+00 2076700300027 9.1300E+01 1.0100E+01 8.6000E-01 9.1000E+00 1.0500E+01 1.3900E+012076700300028 2.0000E+00 2076700300029 1.0600E+02 1.2300E+01 8.0000E-01 3.9000E+00 1.0000E+01 1.0700E+012076700300030 1.0000E+00 2076700300031 1.0930E+02 1.2800E+01 8.6000E-01 7.3000E+00 9.5000E+00 1.2000E+012076700300032 2.0000E+00 2076700300033 1.2980E+02 1.6200E+01 8.2000E-01 3.0000E+00 9.3000E+00 9.8000E+002076700300034 1.0000E+00 2076700300035 1.3330E+02 1.6800E+01 8.6000E-01 6.3000E+00 9.1000E+00 1.1100E+012076700300036 2.0000E+00 2076700300037 1.6250E+02 2.2100E+01 6.9000E-01 3.1000E+00 1.0300E+01 1.0800E+012076700300038 1.0000E+00 2076700300039 1.6630E+02 2.2700E+01 7.5000E-01 6.2000E+00 1.0100E+01 1.1800E+012076700300040 2.0000E+00 2076700300041 2.0950E+02 3.1400E+01 4.2000E-01 6.2000E+00 1.6600E+01 1.7700E+012076700300042 1.0000E+00 2076700300043 2.1320E+02 3.1800E+01 5.4000E-01 1.1500E+01 1.5800E+01 1.9600E+012076700300044 2.0000E+00 2076700300045 ENDDATA 36 0 2076700300046 ENDSUBENT 45 0 2076700399999 ENDENTRY 3 0 2076799999999